Organic structure databases

It makes little sense to search organic and metal organic structures database if the material from which powder diffraction data were collected is inorganic, and vice versa. 

The most difficult application of protein structure comparison comes in classifying known protein structures into different clusters corresponding to fold families. The role of such classifications is to organize structure databases such as the PDB, in hopes of detecting similarities at the structure level that... 

The ROSDAL (Representation of Organic Structures Description Arranged Linearly) syntax was developed by S. Welford, J. Barnard, and M.F. Lynch in 1985 for the Beilstein Institute. This line notation was intended to transmit structural information between the user and the Beilstein DIALOG system (Beilstein-Ohlme) during database retrieval queries and structure displays. This exchange of structure information by the ROSDAL ASCII character string is very fast. 

The user is often more interested in the contents than in the technical organization of databases. The wide variety of data allows the classification of databases in chemistry into literature, factual (alphanumeric), and structural types (Figure 5-10) [12, 13). 

The two major databases containing information obtained from X-ray structure analysis of small molecules are the Cambridge Structural Database (CSD) [25] and the Inorganic Crystal Structure Database (ICSD) [26] both are available as in-house versions. CSD provides access to organic and organometallic structures (mainly X-ray structures, with some structures from neutron diffraction), data which are mostly unpublished. The ICSD contains inorganic structures. 

The abbreviation QSAR stands for quantitative structure-activity relationships. QSPR means quantitative structure-property relationships. As the properties of an organic compound usually cannot be predicted directly from its molecular structure, an indirect approach Is used to overcome this problem. In the first step numerical descriptors encoding information about the molecular structure are calculated for a set of compounds. Secondly, statistical methods and artificial neural network models are used to predict the property or activity of interest, based on these descriptors or a suitable subset. A typical QSAR/QSPR study comprises the following steps structure entry or start from an existing structure database), descriptor calculation, descriptor selection, model building, model validation. 

Cambridge Structural Database (CSD). Cambridge Crystallographic Data Centre, University Chemical Laboratory, Cambridge, UK. Electronic database of crystal structures of organic and metallorganic compounds. www.ccdc.cam.ac.uk. 

AUen, F. H. and Motherwell, W. D.S. (2002). Apphcations of the Cambridge Structural Database in organic chemistry and crystal chemistry. Acta Crystallogr. B 58,407-A22. 

Cambridge Structural Database. A collection of >270K experimental structures for organic and organometallic compounds from X-ray crystallography and neutron diffraction. 

Whereas 2D databases of compounds play an invaluable role in pharmaceutical discovery research, a computational chemistry calculation on a molecule often requires its 3D structure. An excellent starting point for such a calculation is sometimes one of the molecules in the Cambridge Structural Database (CSD), a 3D database. The CSD (24-26) presently has atomic co-ordinates and other information for over 300,000 small organic and organometallic compounds, most of which have been solved by x-ray crystallography. The number of structures in the database is growing by about 10%... 

Blatov, V. A., Carlucci, L., Ciani, G., Proserpio, D. M., Interpenetrating metal-organic and inorganic 3D networks a computer-aided systematic investigation. Part I. Analysis of the Cambridge structural database. Crystengcomm 2004, 6, 377-395. 

Scheme 3 Relative percentages of organic, organometallic and coordination polymorphic compounds present in the Cambridge Structural Database (CSD, version October 2001) [20a],...

The Cambridge Crystallographic Data Centre produces the Cambridge Structural Database (http //www.ccdc.cam.ac.uk/products/csd/), which covers organic and metal-organic small-molecule crystal structures. 

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